<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>西游记之西天取经</title>
		<style type="text/css">
			body {
				background: url(images/background.webp) no-repeat;
				background-size: cover;
				overflow-y: hidden;
			}
			.playground {
				width: 800px;
				margin: 400px auto; 
				overflow: hidden;
			}
			.actor { 
				float: left;
			}
			.actor:first-child {
				width: 200px;
				height: 180px;
				background: url(images/west_01.png) no-repeat;
				/* TODO 填空 */
				animation: a1 0.8s steps(8) infinite;
			}
			.actor:nth-child(2) {
				width: 200px;
				height: 180px;
				background: url(images/west_02.png) no-repeat;
				/* TODO 填空 */
				animation: a2 0.8s steps(8) infinite;
			}
			.actor:nth-child(3) {
				width: 170px;
				height: 240px;
				background: url(images/west_03.png) no-repeat;
				/* TODO 填空 */
				animation: a3 0.8s steps(8) infinite; 
			}
			.actor:last-child {
				width: 210px;
				height: 200px;
				background: url(images/west_04.png) no-repeat;
				/* TODO 填空 */
				animation: a4 0.8s steps(8) infinite;
			}
			@keyframes a1{
				from{
					background-position-x: 0;
				}
				to{
					background-position-x: -1600px;
				}
			}
			@keyframes a2{
				from{
					background-position-x: 0;
				}
				to{
					background-position-x: -1600px;
				}
			}
			@keyframes a3{
				from{
					background-position-x: 0;
				}
				to{
					background-position-x: -1360px;
				}
			}
			@keyframes a4{
				from{
					background-position-x: 0;
				}
				to{
					background-position-x: -1680px;
				}
			}
		</style>
	</head>
	<body>
		<div class="playground">
			<div class="actor"></div>
			<div class="actor"></div>
			<div class="actor"></div>
			<div class="actor"></div>
		</div>
	</body>
</html>
